Heliconius project 1973-1986
Passiflora Flea Beetle Project

Passiflora oerstedii flower, La Selva
Heliconius cydno (?) larva on P. costricensis (?)

 

Heliconius project 1973-1986

Heliconius cydno, La Selva
Numbered H. hecale gathering pollen from Psiguria flower

 

Passiflora Flea Beetle Project

Summary: As documented in Smiley 1982 (see citation below; also see Table 1 below), I found a remarkable similarity between two guilds of herbivores which feed at ground level on the new shoots of Passiflora vines: Heliconius butterflies and flea beetles (Chrysomelidae subfamily Alticini). This finding occurred at the La Selva Biological Station in northeastern Costa Rica, a protected primary rainforest with an extensive system of trails, roads, and experimentally mainpulated areas as well as excellent support facilities. La Selva is characterized by relatively consistent rainfall and high humidity through the year. The Heliconius butterfly and Passiflora vine community is characterized by relatively low, constant population densities which provides an excellent matrix for a parallel Passiflora-feeding flea beetle community (as seen in the cumulative data table Table 2 below). Small numbers of 8 flea beetle species were consistently found on Passiflora species during 3-5 sampling trips to La Selva ( indicated by the orange boxes), suggesting low-density, constant populations.

Unfortunately we know very little about these colorful little insects. My goals in this study are to (1) continue to document host plant use by the flea beetles, (2) rear adults and larvae on different Passiflora vines to look at feeding tolerances and possible toxic feeding restrictions which might cause the parallel patterns of host plant use (3) find a way to look at cyanogenesis by the feeding larvae of both flea beetles and Heliconius. In the photos below, note that seem to be two basic types of flea beetle: slender beetles with parallel sides to the elytra (tentatively identified as genus Monomacra) and "rounder" species with domed elytra and relatively larger legs (tentatively assigned to three genera Strabala, Capraita, and Pedilia).

 

Pedilia flea beetles on Passiflora pittieri at La Selva. These red Pedilia are close to 4mm long. click to enlarge Table 1. "Ancient" graph from article above, comparing guild structure of Heliconius and flea beetles that feed on Passiflora. See Table 2 below for updated version with actual data.
"Blue Flea Beetle" Monomacra violacea chewing Passiflora leaf.
"Red-white Flea Beetle" Strabala sp. Note that, although I was not able to provide scale for these photos, most of the flea beetles are 2-3 mm long not including the antennae.
Black-legged Yellow Monomacra species on P. vitifolia
Flea beetle larva on P. auriculata. Note feeding damage and frass trail. See drawings for more detail.
First quantitative measurements on Passiflora HCN gas production at La Selva. Leaves are weighed, cut into strips, crushed and placed in airtight chamber with "Gasalert Extreme" HCN meter. The meter measures HCN from 0.3 to 30 ppm. This large chamber has a 10 liter volume and therefore holds about 0.45 Moles of gas (at La Selva lab conditions). Smaller chambers can be used to measure smaller quantities of HCN.
Here we are measuring zero parts per million (actually <0.3) of HCN produced by these rapidly feeding Heliconius sara caterpillars, eating leaves of Passiflora auriculata, a weakly cyanogenic species according to our measurements.

La Selva Passiflora-feeding Flea Beetle photo gallery: Black-legged Yellow Monomacra ** Yellow-legged Yellow Monomacra ** Blue Monomacra violacea ** Monomacra chontalensis (?) ** Yellow Strabala ** Red-white Strabala ** Capraita (?) RBrWh ** Red Pedilia sp. ** flea beetle drawings **

Table 2. Cumulative Passiflora x Herbivore Interactions Recorded from La Selva (Flea Beetle I.D.s provisional)
 
Passiflora subgeneric group
DISTEPHANA/PASSIFLORA
 
ASTROPHAEA/DECALOBA
 
Passiflora species
VIT
AMB
QUAD
MEN
OER
 
PIT
LOB
COR
AUR
BIF
COS
 

micromoles HCN outgassed per gram new/old crushed leaves

0/0
22/3
-
22/11
0/0
24/30
0/0
2/-
3/1
10/3
12/17
Flea Beetle morphospecies short name not to scale
 
Monomacra violacea (?) Blue
3(2)
6(4)
-
 
8(4)
 
1(1)
67(14)
-
23(15)
26(8)
3(1)
Monomacra sp.
Slender Yellow (split 2009)
see below
18(13)
4(2)
7(2)
 
22(8)
 
2(1)
3(1)
-
5(5)
3(3)
1(1)
Black Legs 8(4) 2(1)     7(3)           1(1)  
Yellow Legs 1(1)       1(1)     1(1)   8(7) 3(3)  
Strabala sp.1 Fat yellow
no photo
3(3)
20(7)
-
 
9(4)
 
-
-
-
-
-
-
M. chontalensis (?) Red/Black
-
-
-
 
-
 
-
4(3)
-
-
4(3)
-
Strabala sp 2 Red/white
-
-
-
 
-
 
-
64(20)
-
4(1)
-
-
Capraita sp. (?) Red/brown/white
-
-
-
 
-
 
-
1(1)
-
15(14)
9(9)
-
Pedilia sp 1 Red Pedilia
-
-
-
 
-
 
36(3)
-
-
-
-
-
Disonycha sp. Striped  
-
-
-
 
-
 
-
-
-
1(1)
4(2)
-
                             
Alticini sp 3 Brown                        
1(1)
Alticini sp 4 ??                
1(1)
       
                             
Heliconius butterfly,
known host plants
                           
cydno                            
hecale                            
melpomene                            
charitonia                            
erato                            
hecalesia                            
sara                            
sappho                            
                             
data = number of flea beetles seen(number of different Passiflora plants)
Legend:
flea beetle surveys in:
1976-77 (many days),
1991 (2 days),
2009 (4 days)
2010 (9 days)
2011 (8 days)
seen in one survey
 
seen in two surveys
 
seen in three surveys
 
seen in four surveys
 
seen in all five surveys
 

Passiflora species groups
Passiflora group Passiflora subgenus abbreviation Passiflora species name
Passiflora Distephana VIT vitifolia
  Passiflora AMB ambigua
  Passiflora QUAD quadrangularis
  Passiflora OER oerstedii
  Passiflora MEN menispermifolia
Astrophaea/Decaloba Astrophaea PIT pittieri
  Decaloba LOB lobata
  Decaloba COR megacoriacea
  Decaloba AUR auriculata
  Decaloba BIF biflora
  Decaloba COS costaricensis