442 MEANS OF DEFENCE OF INSECTS. 



make the series of imitations complete, a minute black beetle, with ridges 

 upon its elytra (Onthophilus sulcatus^), when lying without motion, is 

 very like the seed of an umbelliferous plant. The dog-tick is not unlike 

 a small bean; which 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 singu- 

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

 the offspring of a particular genus of flies (Volucclla), many of the spe- 

 cies of which strikingly resemble those bees in shape, clotliing, and color. 

 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 

 Bombiis^ JRaieUus, but we could not ascertain what the fly was. Perhaps 

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

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

 that he has discovered that the larvse 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.5 



The brilliant colors 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 (JSIorpho Menehus), which from 

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

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

 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 colors, 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.*^ 



The frightful aspect of certain insects is another passive means of defence 



• Oliv. Entomohsr. \. no. 8. 17. 2 Latreille, Gen. Crust, et Ins. iv. 322. 

 3 Apis.**, e. 2. K. 



* 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 

 tha.t 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. 6 Latreille, Annul, du Mus. 1810, 5. 



