NECTAR CONSUMERS - Nectaries and Nectar - page 303

Table 3. Optimum nectar concentrations for various animal taxa based on empirical measure-
ments of sucrose intake rate. (See references for experimental details.)

Taxon Species Conc.

(% w/w)

Reference

Fruit fly Ceratitis capitata 24 Warburg & Galun, 1992

Hawkmoths Macroglossum stellatarum 34 Josens & Farina, 2001

Butterflies Thymelicus lineola 40 Pivnick & McNeil, 1985

Agraulis vanillae 40 May, 1985

Phoebis sennae
Vanessa cardui

30-40
31-44

May, 1985
Hainsworth et al., 1991

Orchid bees Euglossa imperialis 35 Borrell, 2004

Bumblebees Bombus species 50-65 Harder, 1986

Honeybees Apis mellifera 60 Roubik & Buchmann, 1984

Stingless bees Melipona species 60 Roubik & Buchmann, 1984

Ants Camponotus mus 43 Josens et al., 1998

Camponotus rufipes 40 Paul & Roces, 2003

Pachycondyla villosa 50 Paul & Roces, 2003

Hummingbirds Selasphorus rufus 40-45 Tamm & Gass, 1986

Sunbirds Nectarinia chalybea 30 C.A. Beuchat & S.W.

Nicolson, unpublished data

Honeyeaters Acanthorhynchus tenuirostris 30-40 Mitchell & Paton, 1990

Phylidonyris novaehollandiae 40-50 Mitchell & Paton, 1990

Bats Glossophaga soricina

antillarum

60 Roces et al., 1993

male spermatophores (Boggs et al., 1981). Boggs (1997) used radiotracers to
examine the use of glucose and amino acids acquired during the larval and
adult stages of two nymphalid butterflies. Glucose and amino acids labelled
with the isotopes 14 C and 3 H were painted on leaves for the caterpillars or
included in nectar solutions for the butterflies. Because the adult diet is car-
bohydrate-rich, incoming glucose was used in preference to stored glucose,
while juvenile reserves of amino acids were used throughout adult life. Be-
cause female Lepidoptera can synthesize non-essential amino acids from
nectar sugars and derive essential amino acids from the larval diet (O'Brien
et al., 2002), the role of nectar amino acids in egg manufacture and adult fit-
ness may have been underestimated. Recently, it has been shown that
increased mating frequency decreases the preference of female butterflies
( Pieris napi ) for nectar-containing amino acids (Mevi-Schütz & Erhardt,
2004), and that nectar amino acids can be used to compensate for poor larval
food. Increased fecundity was evident in females raised on low-quality nettle