Letter from the Editor: special issue of papers on “The Use of Native Insect Herbivores for the Management of Eurasian Watermilfoil," presented at a special session of the Annual Meeting, Aquatic Plant Management Society, July 1998, Memphis, TN

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Eurasian watermilfoil biomass associated with insect herbivores in New York

A study of aquatic plant biomass within Cayuga Lake, New York spans twelve years from 1987-1998. The exotic Eurasian watermilfoil ( Myriophyllum spicatum L.) decreased in the northwest end of the lake from 55% of the total biomass in 1987 to 0.4% in 1998 and within the southwest end from 50% in 1987 to 11% in 1998. Concurrent with the watermilfoil decline was the resurgence of native species of submersed macrophytes. During this time we recorded for the first time in Cayuga Lake two herbivorous insect species: the aquatic moth Acentria ephemerella , first observed in 1991, and the aquatic weevil Euhrychiopsis lecontei , first found in 1996 . Densities of Acentria in southwest Cayuga Lake averaged 1.04 individuals per apical meristem of Eurasian watermilfoil for the three-year period 1996-1998. These same meristems had Euhrychiopsis densities on average of only 0.02 individuals per apical meristem over the same three-year period. A comparison of herbivore densities and lake sizes from five lakes in 1997 shows that Acentria densities correlate positively with lake surface area and mean depth, while Euhrychiopsis densities correlate negatively with lake surface area and mean depth. In these five lakes, Acentria densities correlate negatively with percent composition and dry mass of watermilfoil. However, Euhrychiopsis densities correlate positively with percent composition and dry mass of watermilfoil. Finally, Acentria densities correlate negatively with Euhrychiopsis densities suggesting interspecific competition.

Control of insect infestation in smoked West African sardines Sardinella maderensis 'Sawa' using actellic 50 EC solution

Fish which has been cured or are in the process of being cured by traditional methods are usually infested by insects, posing a real problem to traders and processors, especially in Nigeria. The effects of 0.03% actellic 50 EC solution and vegetable oil on insect infestion were studied using West African sardines, Sardinella maderensis. Actellic solution was more effective in combating insect infestation than vegetable oil. Appearance and perceived smoked fish flavour of fish treated with Actellic and vegetable oil differed (P<0.05), while taste was unaffected by treatment. Actellic 50 EC solution though effective, could be subject to abuse

Engineered underdominance as a method of insect population replacement and reproductive isolation

Insect vector-borne diseases, such as malaria and dengue fever (both spread by mosquito vectors), continue to significantly impact health worldwide, despite the efforts put forth to eradicate them. Suppression strategies utilizing genetically modified disease-refractory insects have surfaced as an attractive means of disease control, and progress has been made on engineering disease-resistant insect vectors. However, laboratory-engineered disease refractory genes would probably not spread in the wild, and would most likely need to be linked to a gene drive system in order to proliferate in native insect populations. Underdominant systems like translocations and engineered underdominance have been proposed as potential mechanisms for spreading disease refractory genes. Not only do these threshold-dependent systems have certain advantages over other potential gene drive mechanisms, such as localization of gene drive and removability, extreme engineered underdominance can also be used to bring about reproductive isolation, which may be of interest in controlling the spread of GMO crops. Proof-of-principle establishment of such drive mechanisms in a well-understood and studied insect, such as Drosophila melanogaster, is essential before more applied systems can be developed for the less characterized vector species of interest, such as mosquitoes. This work details the development of several distinct types of engineered underdominance and of translocations in Drosophila, including ones capable of bringing about reproductive isolation and population replacement, as a proof of concept study that can inform efforts to construct such systems in insect disease vectors.

A new technique to control insect infestation in Mas min

A process of heat treating Mas min at 125°C for 15 minutes and hermetically packing them up has been investigated. This method has been found to be successful in controlling insect infestation in Mas min. The Japanese method of packing Mas min in BHC coated containers has also been simultaneously examined and found successful under certain conditions. However, this process is found to impart slight undesirable flavors to the product. In addition, this chemical treatment is also likely to be more costly.

Identification and characterization of insect-specific proteins by genome data analysis

Background: Insects constitute the vast majority of known species with their importance including biodiversity, agricultural, and human health concerns. It is likely that the successful adaptation of the Insecta clade depends on specific components in its

Modeling natural sounds with modulation cascade processes

Natural sounds are structured on many time-scales. A typical segment of speech, for example, contains features that span four orders of magnitude: Sentences ($\sim1$s); phonemes ($\sim10$−$1$ s); glottal pulses ($\sim 10$−$2$s); and formants ($\sim 10$−$3$s). The auditory system uses information from each of these time-scales to solve complicated tasks such as auditory scene analysis [1]. One route toward understanding how auditory processing accomplishes this analysis is to build neuroscience-inspired algorithms which solve similar tasks and to compare the properties of these algorithms with properties of auditory processing. There is however a discord: Current machine-audition algorithms largely concentrate on the shorter time-scale structures in sounds, and the longer structures are ignored. The reason for this is two-fold. Firstly, it is a difficult technical problem to construct an algorithm that utilises both sorts of information. Secondly, it is computationally demanding to simultaneously process data both at high resolution (to extract short temporal information) and for long duration (to extract long temporal information). The contribution of this work is to develop a new statistical model for natural sounds that captures structure across a wide range of time-scales, and to provide efficient learning and inference algorithms. We demonstrate the success of this approach on a missing data task.

Accumulation of hepatotoxic microcystins in freshwater mussels, aquatic insect larvae and oligochaetes in a large, shallow eutrophic lake (Lake Chaohu) of subtropical China

This paper studied the seasonal changes of two common microcystins (MCs), MC-RR and -LR, in the commercially important mussel Corbicula fluminea in Lake Chaohu, where there occurred dense cyanobacteria. Occasional measurements were also made for MC in the mussel Arconaia lanceolat, the oligochaete Limnodilus hoffineisteri and the insect larva Chironomus sp. Mean MC of C. fluminea was much higher in hepatopancreas than in intestine and foot. Our study is the first to report accumulation of MCs in oligochaetes and aquatic insect larvae. The hi-h contents of MCs in the insect larvae suggest a great possibility for the transfer of MCs to benthos-feeding omnivores like common carp. According to the provisional standard by the WHO, 28.6% of the collected C. fluminea were harmful for human consumption, assuming a daily consumption of 300 by a person. It is recommended that edible mussels should not be collected for human consumption during toxic cyanobacterial blooms in Lake Chaohu.

Simultaneous production of low- and high-frequency sounds by neonatal finless porpoises

Phocoenids are generally considered to be nonwhistling species that produce only high-frequency pulsed sounds. Here our results show that neonatal finless porpoises (Neophocaena phocaenoides) frequently produce clear low-frequency (2-3 kHz) pulsed signals, without distinct high-frequency energy, just after birth and can produce both low- (2-3 kHz) and high-frequency (>100 kHz) pulsed signals simultaneously until about 20 days postnatal. The results indicate that low-frequency signals of neonatal finless porpoises are not an early form of high-frequency signals and suggest that low- and high-frequency signals may be produced by different sound production mechanisms. (C) 2008 Acoustical Society of America.

Echolocation click sounds from wild inshore finless porpoise (Neophocaena phocaenoides sunameri) with comparisons to the sonar of riverine N. p. asiaeorientalis

Acoustic signals from wild Neophocaena phocaenoides sunameri were recorded in the waters off Liao-dong-wan Bay located in Bohai Sea, China. Signal analysis shows that N. p. sunameri produced "typical" phocoenid clicks. The peak frequencies f(p), of clicks ranged from. 113 to 131 kHz with an average of 121 +/- 3.78 kHz (n=71). The 3 dB bandwidths Delta f ranged from 10.9 to 25.0 kHz with an average of 17.5 +/- 3.30 kHz. The signal durations At ranged from 56 to 109 mu s with an average 80 +/- 11.49 mu s. The number of cycles N, ranged from 7 to 13 with an average of 9 +/- 1.48. With increasing peak frequency there was a faint tendency of decrease in bandwidth, which implies a nonconstant value of f(p)/Delta f. On occasion there were some click trains with faint click energy presenting below 70 kHz, however, it was possibly introduced by interference effect from multiple pulses structures. The acoustic parameters of the clicks were compared between the investigated population and a riverine population of finless porpoise. (c) 2007 Acoustical Society of America.

Purification of human tissue prokallikrein excreted from insect cells by liquid chromatography

Tissue kallikrein, generally existing in living bodies as prokallikrein, is a serine proteinase that has proven of great significance to treat hypertension, cardiopathy and nephropathy. Although the extraction of tissue kallikrein from human urine is the most commonly used method to obtain such a protein, not only the yield is very little, but also the procedure is rather complex. Furthermore, the biological safety is uncertain. Therefore, the preparation of such a protein by genetic engineering method, including gene expression, cell culture, separation and purification, is very important. In this paper, a new method to obtain purified tissue prokallikrein excreted from insect cells by liquid chromatography has been proposed. In contrast to the previously published papers, the purification procedure is simplified to only three steps with the final yield of 57% and the purity of 95%, which is not only convenient, but also low-cost and suitable for the large-scale preparation of such a protein. The purified protein is further validated as prokallikrein by high performance liquid chromatography-mass spectrometry and amino acid sequencing. (c) 2005 Elsevier B.V. All rights reserved.

Electron tomography of cryofixed, isometrically contracting insect flight muscle reveals novel actin-myosin interactions.

BACKGROUND: Isometric muscle contraction, where force is generated without muscle shortening, is a molecular traffic jam in which the number of actin-attached motors is maximized and all states of motor action are trapped with consequently high heterogeneity. This heterogeneity is a major limitation to deciphering myosin conformational changes in situ. METHODOLOGY: We used multivariate data analysis to group repeat segments in electron tomograms of isometrically contracting insect flight muscle, mechanically monitored, rapidly frozen, freeze substituted, and thin sectioned. Improved resolution reveals the helical arrangement of F-actin subunits in the thin filament enabling an atomic model to be built into the thin filament density independent of the myosin. Actin-myosin attachments can now be assigned as weak or strong by their motor domain orientation relative to actin. Myosin attachments were quantified everywhere along the thin filament including troponin. Strong binding myosin attachments are found on only four F-actin subunits, the "target zone", situated exactly midway between successive troponin complexes. They show an axial lever arm range of 77°/12.9 nm. The lever arm azimuthal range of strong binding attachments has a highly skewed, 127° range compared with X-ray crystallographic structures. Two types of weak actin attachments are described. One type, found exclusively in the target zone, appears to represent pre-working-stroke intermediates. The other, which contacts tropomyosin rather than actin, is positioned M-ward of the target zone, i.e. the position toward which thin filaments slide during shortening. CONCLUSION: We present a model for the weak to strong transition in the myosin ATPase cycle that incorporates azimuthal movements of the motor domain on actin. Stress/strain in the S2 domain may explain azimuthal lever arm changes in the strong binding attachments. The results support previous conclusions that the weak attachments preceding force generation are very different from strong binding attachments.