MEANS OP DEFENCE OF INSECTS. 407 



resemblance has caused a bean, commonly cultivated as food for horses, 

 to be called the tick-bean. The Palma Christi, also, had probably the 

 name of Ricinus given to it from the similitude of its seed to a tick. 



Another tribe of these little animals, before alluded to, is secured from 

 harm by a different kind of imitation, and affords a beautiful instance of 

 the wisdom of Providence in adapting means to their end. Some singular 

 larvae, with a radiated anus \ live in the nests of humble-bees, and are the 

 offspring of a particular genus of flies (Volucella), many of the species of 

 which strikingly resemble those bees in shape, clothing, and colour. Thus 

 has the Author of nature provided that they may enter these nests and 

 deposit their eggs undiscovered. 



Did these intruders venture themselves amongst the humble-bees in a 

 less kindred form, their lives would probably pay the forfeit of their pre- 

 sumption. Mr. Sheppard once found one of these larvae in the nest of 

 Bombus* Raiellus, but we could not ascertain what the fly was. Perhaps 

 it might be Volucella bombylans, which resembles those humble-bees that 

 have a red anus. 3 In like manner Mr. W. S. MacLeay informs us 

 that he has discovered that the larvae of those tropical Bombylii which 

 have such a bee-like form live on the larvae of the bees they so strikingly 

 represent ; and he suggests that probably the object of nature in giving 

 such an ant-like form to the singular spider described by him under the 

 name of Myrmarachne melanocephala is to deceive the ants on which they 

 prey. 4 



The brilliant colours in which many insects are arrayed may decorate 

 them with some other view than that of mere ornament They may dazzle 

 their enemies. The radiant blue of the upper surface of the wings of a 

 giant butterfly, abundant in Brazil (Morpho Menelaus), which from its 

 size would be a ready prey for any insectivorous birds, by its splendour 

 (which I am told, when the insect is flying in the sunshine, is inconceiv- 

 ably bright) may produce an effect upon the sight of such birds, that may 

 give it no small chance of escape. Latreille has a similar conjecture with 

 respect to the golden wasps (Chrysis L.). These animals lay their eggs in 

 the nests of such Hymenoptera, wasps, bee-wasps (Bembex), and bees, as 

 are redoubtable for their stings ; and therefore have the utmost occasion 

 for protection against these murderous weapons. Amongst other defences 

 the golden wasps are adorned with the most brilliant colours, which, by 

 their radiance, especially in the sunny situations frequented by these insects, 

 may dazzle the eyes of their enemies, and enable them to effect unhurt the 

 purpose for which they were created. 5 



The frightful aspect of certain insects is another passive means of de- 

 fence by which they sometimes strike beholders, especially children, often 

 great insect tormentors, with alarm, and so escape. The terrific and pre- 

 tended jaws of the stag-beetle (Lucanus Cervus) in Europe, and of the 



1 Latreille, Gen. Crust, et Ins. iv. 322. 



2 Apis. * *. e. 2. K. 



5 Dr. Fleming, however (in Literis}, doubts whether the reason here assigned is 

 the cause of the resemblance between the Bombus and Volucella; he thinks if a bee 

 knows a stranger of its own species, it could not be deceived by a fly in the disguise 

 of a bee. But the fact that these insects lay their eggs in their nests, and that they 

 resemble humble-bees, seems to justify the conclusion drawn in the text. They 

 must get in often undiscovered. 



* Ann. Nat. Hist. ii. 12. * Latreille, Annul du Mus. 1810, 5-. 



PD 4 



