INSECTS 



with their life history are so intensely interesting that they are well 

 worthy of far greater attention than they have hitherto received. It has 

 been already stated that the females greatly outnumber the males, but in 

 many cases the males are quite unknown and in some species only females 

 are believed to be produced. Parthenogenesis is extremely common 

 among them, and though in some instances ova deposited by virgin females 

 have produced males, as a rule such ova produce only females, and it has 

 been abundantly proved that these possess the faculty of reproducing their 

 like without any male assistance for an indefinite number of generations. 



Among the more noteworthy species found in the county, attention 

 may be drawn to those of the very handsome genera Lyda, Abia and Arge , 

 which are well represented. Three species of Do/erus (D. rugu/osus, 

 D. fumosus and D. gibbosus) are as yet only known as British from 

 examples captured near Colchester, where Loderus palmatus is occasionally 

 found. The rare Macrophya rufipes is also worthy of mention, and 

 Allantus jlavipes is from a collector's point of view a good insect, as it is 

 not often obtained in Britain and is scarce elsewhere. Several specimens 

 were found on charlock flowers near Langham Lodge Wood many years 

 ago, but none have occurred recently. The male of Strongylogaster cingu- 

 latus is accounted a rarity though the female is abundant, but one day in 

 the spring of 1899, in Donyland Wood, several males were captured 

 before any females had been seen, which is contrary to Mr. Cameron's 

 experience, as he states that though he has bred hundreds of females he 

 only succeeded in getting one male, which curiously enough appeared 

 some days after all the females of the same batch had emerged. As two 

 of his virgin females produced fertile eggs he concludes that partheno- 

 genesis plays a constant r61e with this species. Allantus zona is another 

 scarce species which has occurred at St. Osyth. 



The Gallflies (Cynipida) form those abnormal growths upon trees 

 and plants of which the oakapple, the marble and woody galls of the oak, 

 and the moss-like Bedeguar gall of the rose are familiar and conspicuous 

 examples, but all gall-producing insects are not Hymenopterous, as many 

 of them belong to other orders, such as the Gall-gnats (Cecidomyida) 

 among the Diptera and certain of the Aphides and beetles. 



The facts and problems connected with the reproduction of the 

 Cynipidce are even more interesting and complicated than in the case of 

 the Tenthredinida, and though it is impossible to go fully into them here, 

 it may be briefly stated that some insects which were formerly believed 

 to be distinct are now known to be different forms of the same species, 

 which inhabit totally dissimilar galls and appear at different times of the 

 year, the earlier brood consisting of both males and females and the later 

 brood of females only, which lay fertile eggs and produce the bisexual 

 brood of the following season. 



But besides this alternation of generations, there are other species 

 which are well known to be single brooded and which consist of females 

 only, for though they have been bred by hundreds of thousands by 

 different investigators, all endeavours to discover the males have been 



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