| Spiders is the important natural enemies of pests in agriculture and forestry ecological system. In order to master behavior and habits of Allagelena difficilis, a important natural enemy of gardens and orchards insect pests, to provide the basis for its potential application evaluation, and to formulate ecological control strategy of insect pests, the predation behavior, courtship behavior, copulatory behavior and spawn behavior were studied under laboratory conditions. The sense of visual and olfactory were tested and analysed to help to understand A. difficilis how to discover and catch their preys. The main results are as follows:1. The predation behavior and efficiency controling insects of A. difficilisThe studies in laboratory showed that immature and mature A. difficilis have similar spectrum of predatory behavior, including closing to, ranning to, testing, catching, sucking, residue treatment, cleaning appendage, resting and so on. But the specific process is different in some extent. It mainly shows that body size of preys can effect the attacking stage of spiderlings and adults. When spiderlings can only suck a single prey, adults can suck one more preys. After finishing treating residue of preys, spiderlings always directly go into rest, but adults often circle around and netting, and then resting.The functional reaction of the female adult A. difficilis preying on Drosophila melanogaster accorded with Holling II equation, Na=1.003N/(1+0.0025N), r2=0.98, the instantaneous attack rate came to0.95. The non pregnant female of adults have similar predation quantity with male adults (P>0.05), but the female pregnant A. difficilis’s predation is significantly higher than the male ones (P<0.05). Compare the predation between the bottle containing two female A.difficilis and two different sex of A.difficilis, the result showed that they are siginificantly difference(P<0.01). A female and a male of A. difficilis were killed in the bottle which containing different sexes,13A. difficilis were killed in the bottle containing two female A. difficilis.2. A. difficilis’s feel factor of preyY-tube olfactometer test results showed that the number of A.difficilis who choose correct direction of prey are similar to those who choose opposite direction (P>0.05), prompting smell has little influence on predation behavior. Visual shielding test results, A. difficilis which eyes are blacked with ink are not siginificantly difference comparing to those which are not with ink in predation (P>0.05).Compare the predation of web removed A. difficilis to webbed ones, the result showed that they are siginificantly difference (P<0.05) in early hours, Because A. difficilis can also prey after removing web a few hours, but the quantity is small. With web repairing, the predation of web removed spiders is similar to webbed ones. The above results indicated, A. difficilis find and prey on mainly not through the visual and smell, but primarily through touch and web vibration, and touching or hearing may be the important factor effecting the predation of A. difficilis.3. The courtship, copulating, spawning and hatching behavior of A.difficilisBefore they copulate, male A. difficilis appear a series of complex courtship behavior, including abdomen rhythmicity vibrating, pedipalps knocking net and so on. The rhythmicity vibrating of male reaches4times per second. After female A. difficilis accept male one’s courtship for a few minutes, they start mating. Male A. difficilis use pedipalp insert into reproductive organs of female A. difficilis when copulating periods, insert times come average29times. Copulating lasting average31mins per time.Female A. difficilis weave oval cocoon, and lay eggs on it, then weave web to pack eggs. From courting to spawning it needs average13days, and64days needed from spawning to hatching it. The hatching rate of the eggs comes to48.49%. The second copulating of male and female A. difficilis is also observed. |
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