Sawfly

Materials produced by crystalliferous bacilli which elicit a toxic response in susceptible insects may be separated into two types. The first type, the true toxins, include the crystalline protein inclusion body the parasporal body of Hannay (14)], a heat-stable, water-soluble exotoxin active against flies, a heat-stable, dialyzable water-soluble exotoxin, toxic to Lepidoptera on injection (23), and a heat-labile, water-soluble, filterable exotoxin, toxic toward larch sawfly larvae (Hymenoptera) which was reported by Smirnoff (31). 

Type 3. A heat-labile material, toxic on ingestion to several species of larch sawfly (31). 

The exotoxin reported by Smirnoff (31) is definitively different from other soluble toxins, as indicated by its reported heat lability. This soluble toxin was obtained from the supernatant of a sporulated B. thuringiensis culture. In testing, it was found to be very toxic by ingestion to 18 species of larch sawfly larvae. No further studies on this toxin have been reported at this time. 

Mortality in larch sawfly larvae May be partially responsible for gut cell destruction... 

JR,9Z)-9-Octadecen-4-olide (30) is the female pheromone of the currant stem girdler (currant sawfly, Janus integer). Both the enantiomers of 30 were synthesized as summarized in Scheme 44 [69]. Lipase-catalyzed asymmetric acetylation of ( )-A was the key-step to give unreacted CR)-A and acetylated (S)-B. 

This chapter reviews the literature of semiochemical (mostly pheromone) identification in Hymenoptera published since 1990. For this review, we separate the order Hymenoptera into the following three, somewhat overlapping, classes to reflect their differences in biology and semiochemistry solitary, parasitic, and social (Table 1). Although there is considerable literature on the semiochemical activity of specific glandular extracts and the chemical composition of specific glands, only those chemicals with demonstrated pheromonal (or semiochemical) activity will be specifically discussed here. The earlier literature of pheromones in social hymenoptera has previously been reviewed [4-6]. There have been more recent reviews of pheromones in social hymenoptera [7-10], parasitic wasps [11,12], sawflies and seed wasps [13,14], and mating pheromones across Hymenoptera [15]. 

All of the suborder Symphyta and many species in the superfamily Aculeata in the suborder Apocrita are solitary insects. Although not requiring the complex semiochemistry of parasitic or social insects, solitary insects employ pheromones for mating, territorial marking, and host marking. Unfortunately, very few of these have been chemically identified. The pheromones of sawflies and seed wasps were extensively reviewed in 1999 [ 14]. The semiochemicals recently identified in solitary hymenoptera, discussed below, are summarized in Table 2 and Fig. 1. 

The importance of the three stereogenic centers became evident as two of the stereoisomers [(2S,3S,7S) and (2S,3R,7R)] were recognized early as sex pheromones and that other enantiomers and diastereoisomers were often found to be inhibitory to the attractive response. Recently, the sawfly pheromone field has undergone a major advance with the recognition that several sawfly species synthesize and utilize sex pheromones of different structural types than the 3,7-dimethylpentadecan-2-ols. Shorter and longer chain lengths (undecan-2-ols 2 and tridecan-2-ols 3) and an additional methyl group in position 9 or 11 (4 and 5) characterize these new pheromone discoveries (Fig. 1). With an ad-... 

The field response of the European pine sawfly, Neodiprion sertifer, to the acetate of (2S,3S,7S)-3,7-dimethylpentadecan-2-ol 1 and the effect of the (2S,3R,7R)-iso-mer was studied from Japan in the east to Canada in the west. The addition of the (2S,3R,7R)-isomer was benign in Japan, inhibitory in Europe with the inclusion of as little as 1%, and its presence essential in Siberia. These findings will allow for the development of a more efficient N. sertifer monitoring scheme without having to determine the stereochemistry produced in each population [27]. 

In Kentucky, the acetate of (2S,3S,7S)-3,7-dimethylpentadecan-2-ol 1 was used to assess the population density and flight activity of the European pine sawfly, N. sertifer, amongst the loblolly pine sawfly, N. taedae linearis, and the redheaded pine sawfly, N. lecontei. [28]. The results indicated that, although present, N. sertifer was a minor participant in sawfly populations. 

Anderbrant O (1993) Pheromone biology of sawflies. In Wagner MR, Raffa KF (eds) Sawfly life history adaptations to woody plants. Academic Press, San Diego, p 119... 

Anderbrant O (1999) Sawflies and seed wasps. In Hardie J, Minks AK (eds) Pheromones of non-lepidopteran insects associated with agricultural plants. CABI Publishing, New York, p 199... 

Narayanan K, Gopalakrishnan C. Evaluation of entomopathogenic nematode, Steinemema feltiae against field population of mustard sawfly, Athalia lugens proxima (Klug) on radish. Int J Exp Biol. 2003 41 376-378. 

Many sawfly larvae protect themselves against predation by sequestering toxic metabolites from their host plant. One strategy is to store these compounds in... 

Clockwise from top left) Plant problems Pea plants stressed by drought and heat leaf yellowing between the veins, a common symptom of mineral deficiency red currant bush with most of its leaves stripped to skeletons by the pest gooseberry sawfly the fungal disease potato blight... 

Many eaterpillars (here of a sawfly), adult beetles and their grubs, and of eourse slugs and snails, graze on leaves and sometimes stems. Other larvae mine or tunnel leaves. Leaf damage reduees the area where photosynthesis operates, sapping the plant s strength and redueing fruit set. 

Pick up fallen fruitlets, as these may house sawfly larvae. Earwigs may be found on fruits, but do not cause significant damage, and should be tolerated as they are excellent apple pest predators. In fall, remove mulches and rake up all fallen leaves, or mow over them so that they are taken down into the soil quickly, as they may harbor scab spores that could reinfect the tree in spring. Apply grease bands to trees and stakes to deter winter moths keep in place until early spring. After harvest, remove all unpicked fruits from the tree, and hang up fat to attract birds, which eat pests. 

Symptoms Caterpillars cause extensive tunnels through fruit, spoiling it Damaged fruit may ripen and drop prematurely. See also Apple sawfly. 

Adult sawflies are small, inconspicuous, dark-bodied flies up to Vz in (1 cm) long. The larvae, which damage plants, vary in color from cream to green and brown and resemble moth or butterfly caterpillars. They range in size from /2 to 1% in (1.5-3 cm) long. (See also Caterpillars, for comparison.) The larvae feed on leaves, stems, and fruit of a wide range of plants. If infestation is severe, the plant is often reduced to a skeleton. See Apple sawfly. 

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