Proceedings, IDlrl. (51 



SOME OBSERVATIONS ON THE HYMENOPTERA OF THE OKANAGAN. 

 Bv E. P. Venables, Vernon. 



In speaking upon this group of insects, I should state at the outset that I have 

 (hine little active work in the order for some years now. But as I have brought 

 together a fair collection, comprising representatives of most of the families, it may 

 be of interest to give the notes that I have of the various species. 



This district is undoubtedly a favoured spot as regards the Hymenoptera, and 

 careful work among any of the families would bring to light many new and interest- 

 ing forms. During the coming season I propose to work at the sawflies, and shall 

 hope to get some notes of interest. The Hymenoptera include some of the most 

 beneficial and at the same time the most interesting insects known. We have only 

 to consider the vast number of parasitic forms to be found in the superfamilies 

 Ichneumonoidea and Chaleidoidea, without the intervention of which most species of 

 leaf-eating caterpillars would soon devastate all plants, both wild and cultivated. 

 We find in the former group a great assemblage of parasitic forms ranging in size 

 from some 2 inches in length down to others of quite microscopical dimensions. As 

 to numbers, it is enough to state that Ashmead, who worked at the genera of the 

 world, recognized 1,140 distinct genera of these strictly beneficial insects. The Chal- 

 eidoidea is considered to be probably the largest in numbers of species of any of the 

 Hymeuopterous groups ; only a few of these have so far been described. They are 

 with few exceptions parasitic in habit, some of the species being found as egg 

 parasites within the eggs of other insects, a few producing certain plant-galls. 



The ants, bees, and wasps are undoubtedly the most interesting as well as the 

 most highly developed of all insects exhibiting that complicated but orderl.y com- 

 munal life such as is found in every ant-hill or bees' nest, the study of which reveals 

 some almost astounding facts, both as regards division of labour and also, as among 

 ants, symbiosis of a highly complicated nature. 



There are many hundreds of different species of insects found inhabiting the 

 tunnels and galleries of ants' nests in different parts of the world, some of which 

 are able to furnish the ants with certain secretions from glands situated in different 

 parts of the body, as is the case with the larvfe of certain Lycrena, butterflies which 

 are found attended by ants, for the purpose of feeding upon the excretions of honey- 

 dew which is extruded by the Lyctena larva from a specialized gland situated on the 

 dorsal surface of the abdomen. We have also the case well known to all who have 

 paid any attention at all to insects of the consociation of ants and aphides. This 

 well-known phase of ant behaviour has not been acquired by all ants, for although 

 many species have developed the habit and have in the course of time learnt to 

 take great ijains to secure the excretion of the aphides, some species, in fact, building 

 roofs over the colonies of these insects to protect them, others, as e.xampled by 

 certain carnivorous groups, care nothing for the plant-lice and never, so far as is 

 known, feed upon their excretion. It is not uncommon to find in early spring, on 

 opening an ants' nest, numbers of aphis-eggs which have been taken in for protection 

 by the ants in the autumn. When these eggs hatch the ants remove the young 

 aphides to their natural food-plant near the nest, and so ensure a supply of honey- 

 dew for the summer months. There are many other insects found to inhabit ants' 

 nests. Many Coleoptera, Homoptera, and scale-insects may be found. These latter 

 furnish excretion for the ants and are protected by their hosts. 



The beetle Cremastocheilus /pilosicolUs I have found frequently in the galleries 

 of nests beneath stones, etc. Wheeler states that the ants employ themselves gnaw- 

 ing the anterior thoracic angles of these beetles. I might state, to show the intricacy 

 of the phase of the subject, that there have been enumerated by Wassmann no less 

 than 1,24G species of various small animals, " not only inserts, but certain spiders 

 and Crustacea, known to inhabit ants' nests either as true guests, or tolerated 

 .scavengers, or as persecuted intruders." 



